Conventional changeover systems for engines may allow a change in fuel type input to the engine. However, in specific cases, when transitioning from a compression ignited fuel, such as diesel, to a spark ignited fuel, such as gasoline or natural gas, residual by-products resulting from the combustion of the compression ignited fuel may be left behind in a combustion chamber of the engine. Typically, pre-ignition characteristics of spark ignited fuels may be different from that of compression ignited fuels. The residual by-products left behind in the combustion chamber of the engine may cause detrimental effects such as knocking, or detonation from pre-ignition of the spark ignited fuel. Thus, the residual by-products may negatively impact transitioning from compression ignited fuels to spark ignited fuels within the engine and deteriorate engine performance.
U.S. Pat. No. 4,489,699 relates to an apparatus adapted for controlling operation of an internal combustion engine operable selectively on gaseous fuel or liquid fuel. A gaseous fuel supply line extends between the engine and a source of gaseous fuel. A liquid fuel supply line extends between the engine and a source of liquid fuel. A control for controlling supply of the gaseous fuel and the liquid fuel to the engine is provided. The control includes an operator controlled fuel selector switch movable between a gaseous fuel position and a liquid fuel position. In response to movement of the fuel selector switch from the gaseous fuel position to the liquid fuel position, liquid fuel flow is permitted through the liquid fuel supply line. Further, gaseous fuel flow may be continued through the gaseous fuel supply line until initiation of liquid fuel combustion. Thereafter, gaseous fuel flow may be prevented until the fuel selector switch is repositioned to the gaseous fuel position. In response to a movement of the fuel selector switch from the liquid fuel position to the gaseous fuel position, gaseous and liquid fuel flow is prevented until termination of the liquid fuel combustion. Thereafter, gaseous fuel flow is permitted until the fuel selector switch is repositioned to the liquid fuel position.